Uncoupled LAA Device

ABSTRACT

A medical device for treating an LAA is presented. The device includes a cap, a bulb and a joint assembly therebetween. The cap is a three layer mesh structure with a retaining hub securing the layers together. A plurality of proximal wire loops extend from the base layer to a proximal post of the joint assembly. The bulb has a plurality of distal wire loops that extend between a terminal post and a distal post of the joint assembly. The joint assembly comprises a first ball joint, a second ball joint and a housing. Each ball joint is retained in the housing independent ball and socket relationships. Each ball joint and post defines a longitudinal axis. The housing defines a housing longitudinal axis. By way of the ball and socket relationship each ball joint longitudinal axis may form an angle of between about 0 to about 35 degrees with the housing longitudinal axis in any direction.

FIELD OF THE INVENTION

The present invention relates to implanted devices for use in occludingthe left atrial appendage (LAA) of patients. The device includesstructures that permit the device to be easily retrieved and redeployed,as well as structures that provide improved articulation and flexibilityto allow the device to be deployed in the LAA regardless of size, shapeor angle of insertion presented by a patient's anatomy.

BACKGROUND OF THE INVENTION

The heart is generally comprised of four chambers: the left and rightatrium, and the left and right ventricle. Additionally, a small cavitycalled the left atrial appendage (LAA) is located off the left atriumbetween the mitral valve and the left pulmonary vein. Thus, the LAAopens into the left atrium of the heart. The LAA is shaped like a smallthumb which terminates as it tapers away from the opening. The openingitself is referred to as the LAA ostium.

In a healthy heart, the LAA contracts as the heart contracts. Inindividuals diagnosed with atrial fibrillation (AF), however, the LAAmay not contract with enough force to expel all of the blood from theLAA. In individuals diagnosed with AF, the electrical activity of theatrium becomes very rapid and disorganized. Thus, the heart beatsquickly and may not get enough time in between beats to fill up withblood. As a result, only a small amount of blood is pumped out of theheart with each beat, and the cardiac output drops significantly.Therefore, stagnant blood may easily remain in the LAA. Because clottingoccurs when blood is stagnant, clots or thrombi may form in the LAA. Ifa blood clot leaves the LAA and becomes lodged in an artery in thebrain, a stroke results.

The LAA may be sealed off during open heart surgery, which is a risky,painful, and expensive procedure. Surgery for closure of the LAA ismajor heart surgery, which requires the patient to undergo generalanesthesia and opening of the chest cavity. The patient must spendseveral days in the hospital and thereafter may take several weeks to beable to return to normal levels of activity.

To avoid the risks and discomfort associated with open heart surgery,modem occlusion devices have been developed that are small, implantabledevices capable of being delivered to the heart through a catheter.Rather than surgery, a catheter inserted into a major blood vesselallows an occlusion device to be deployed at the defect once the devicehas been moved through the catheter to the treatment site. Thisprocedure is performed in a cardiac cathlab and avoids the risks andpain associated with open heart surgery. These devices have proveneffective at sealing defects in the heart and could likewise be used toocclude the LAA without requiring open heart surgery.

Devices that have received significant clinical study include the“Plaato” device described in U.S. Pat. No. 6,152,144 among others, andthe “Watchman” device described in U.S. Pat. No. 6,689,150 among others.Each of these clinically tested devices lies wholly within the LAA andincludes a membrane that spans the opening or ostium of the LAA. TheWatchman device is typically porous and in the Plaato device themembrane is impervious to the passage of blood. Additionally, theWatchman device uses a series of barbs or prongs which enter the tissuesurrounding the ostium of the left atrial appendage to help secure thedevice during the acute phase of implant.

While devices such as these have been shown to be effective foroccluding the LAA, they nevertheless have drawbacks. For example, suchdevices are often incapable of being readily deployed in anatomieshaving irregularities such as an oddly shaped LAA or that extends atsharp angles from the atrial wall. Similarly, such devices employoccluding baskets or cages of wire mesh that though flexible, may imposetheir shape on the LAA causing the LAA to be distended or irritatedleading to potential post implantation complications. The ability toretrieve and redeploy the devices which may be necessary to achieveproper placement is also problematic with these existing devices. Inmost instances a retrieved device may not be reused and must bereplaced, driving the cost of the therapy up.

Thus, there is a need in the art for an LAA occlusion device which canbe implanted at a wide variety of approach angles and that may beimplanted into the LAA without distorting the shape of the LAA orcausing undue irritation thereto; and which is redeployable tofacilitate reliable implantation.

SUMMARY

The devices and their methods of use described herein differ from priorLAA devices and techniques by providing a device that includes a cage orbulb for deployment within the LAA space that while still supportive ofthe LAA is more flexible than previous devices. In addition, the deviceincludes an articulated joint between the bulb and ostial cap whichallows the relative position between the cap and bulb to be angled orskewed to a greater degree than known LAA occlusion devices. Devices ofthe present disclosure may also include a unique three-layer capstructure which while pliant and conformable to the shape of the ostiumof the LAA, also provides a seal that prevents the passage of clotstherethrough with superior performance over known cap structures.

These and other unique features provide for embodiments of thedisclosure that provide LAA devices, which are highly adaptable for usein any anatomy, and which provide superior LAA occlusioncharacteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of an LAA occlusion device shownin the deployed or fully expanded state.

FIG. 2 is a side view of the embodiment shown in FIG. 1 wherein thedevice is shown deployed in its environment of use.

FIG. 3 is an exploded side view of the embodiment shown in FIG. 1

FIG. 4 is an exploded perspective view of the embodiment shown in FIGS.1-3.

FIG. 5 is a side view of an embodiment of the LAA occlusion device shownin FIG. 1 depicting the degree of potential articulation between the capand the bulb via the connection joint.

FIG. 6 is a close-up side view of the connection joint shown in FIG. 5.

FIG. 7 is a sectional view of the connection joint shown in FIG. 6.

FIG. 8 is a close-up view of the embodiment shown in FIG. 5 with theconnection joint shown in section to illustrate its ability to provideand limit articulation between the cap and bulb.

FIG. 9 is an alternative close-up view of the embodiment shown in FIG. 5with the connection joint shown in section to illustrate its ability toprovide and limit articulation between the cap and bulb.

FIG. 10 is a side view of the device shown in FIG. 5 deployed within aleft atrial appendage having a curved shape.

FIG. 11 is a detailed perspective view of the joint assemblyillustrating its three potential axes of rotation and articulation.

FIG. 12 is a top down perspective view of the joint assembly shown inFIG. 11 depicting the potential full range of motion of the jointassembly components.

FIG. 13 is a side view of an alternative embodiment of the LAA occlusiondevice shown in FIG. 5.

FIG. 14 is a close-up side view of the connection joint assembly shownin FIG. 10.

FIG. 15 is a sectional view of the connection joint assembly shown inFIG. 11.

FIG. 16 is a side view of an embodiment of the LAA device being deployedfrom a catheter and into the LAA.

FIG. 17 is a side view of the embodiment shown in FIG. 16, wherein thedevice is shown deployed with the bulb fully within the LAA and the capextending fully across the ostium.

DETAILED DESCRIPTION

FIG. 1 shows the LAA device 10 shown in its fully expandedconfiguration. The device includes a cap structure 12 and a cage or bulbstructure 14. A connection joint assembly 16 provides a pivoting androtatable joint between the cap 12 and bulb 14.

FIG. 2 shows the device 10 deployed within its intended environment ofuse within the left atrial appendage (LAA) 100. When properly deployedthe cap structure 12 over-lies the annular ostium 102 of the LAA 100with the larger perimeter of the cap engaging or being positionedimmediately adjacent to the surrounding atrial tissue 104. The bulbstructure 14, when properly deployed, engages the walls 106 of the LAAwithout distortion or application of force sufficient to distend oralter the shape of the LAA. The connection joint assembly 16 allow thecap 12 and bulb 14 to be moved and deployed effectively independent ofone another, thus allowing the cap 12 to have a secure engagement acrossthe ostium 102 and the bulb 14 to be firmly positioned within the LAA100 regardless of the shape, or tortuosity of the anatomy.

Turning to the exploded view depictions of the device 10 show in FIGS. 3and 4, here the components of the cap structure 12 and their uniqueconstruction are more clearly shown. The cap 12 is comprised of aplurality of proximal wire supports or loops 20 that extend from thebase layer 32 of the sail or ostial cover 30. Each proximal wire loop 20may be comprised of a single wire 22 (which may be a stranded wire ofmultiple wire filaments with a larger core filament surrounded by up to12 smaller diameter filaments) of a shape memory material such asNitinol. The wire 22 extends from the proximal post 40 of the jointassembly 16 (discussed in greater detail below) to a connection member42, whereupon the wire 22 loops back to the post 40 to complete thestructure of the wire loop 20. Each connection member 42 includes aplurality of through holes 43 (best seen in FIG. 4) through with abio-compatible filament or braid (not shown) may be threaded to securethe cover 30 to each wire loop 22.

In the embodiment shown in FIG. 3-4, the cover 30 is a representativemultilayer structure having a base layer 32 and secondary or “petal”layer 34 and a top layer 36. Base layer 32 and petal layer 34 arecomprised of mesh of any of a variety of bio-compatible materials suchas: polyethylene terephthalate, polyester (DACRON™), Polyvinyl Alcohol(PVA), polyurethane, etc. Layers 32 and 34 may have same of differentporosity and may be woven or manufactured with different thicknesses orother characteristics.

The base layer 32 may be a single unitary piece of mesh material, or asin the embodiment shown in FIG. 4, comprised of two hemi-spheres 31 and33 of material joined together along a common border 35 by sutures orother retaining mechanism. In some embodiments, the base layer iscomprised of multiple joined sections of material of any number desired.The junction of the sections 31 and 33 of the base layer may be achievedby suturing or other engagement mechanism, or by simply allowing theportions to abut or overlap one another at or along the border 35. Byproviding a base layer 32 of multiple sections, tissue in growth ispromoted along the border 35 of the sections 31 and 33 even if theporosity of the mesh prevents or limits such growth.

Turning now to the secondary layer 34, here multiple sections or petals38 of ovoid or elliptical shaped material are arranged in a continuousand overlapping manner with a front edge 37 of a given petal 38positioned either under or over the back edge 39 of the immediatelyadjacent petal 38. As with the border(s) 35 of the base layer 32, theoverlapping arrangement of petals 38.

Finally, the top or securement layer 36 of material is a layer ofsubstantially solid or tightly woven or extruded mesh material havinggreater strength than the under lying layers 32 and 34. The securementlayer's primary function is to act as a buffer and securement surfacefor securing the cover 30, as a whole, to an engagement hub 50. Eachlayer 32, 34 add 36 defines a central opening or hole 52 a, 52, b and 52c (respectively). Through which a portion (or shaft) of the engagementhub 50 passes so as to cinch the layers of the cover 30 together andhold them in place adjacent one another; while simultaneously ensuringthat the cover 30 has sufficient strength to resist tearing ordisruption during the crimping and/or delivery process discussed ingreater detail below.

Turning now to the bulb or cage structure 14, as shown in FIGS. 1-4 andbest seen in FIG. 3, the bulb structure 14 is made up of a collection ofdistal wire loops 60. The distal wire loops 60 comprise a single wire orwire braid 22 that passes through the distal post 44 of the jointassembly 16 and extend to the terminal post 70; with the ends of thewire 22 of each distal loop 60 collected in a crimp coupler 62. Acompanion collar 64 connects the wire 22 of adjacent distal wire loops60, to provide structural stability and support to the bulb structure14. The collars 64 connect immediately adjacent wire loops and permitforces to be shared by the two loops while not influencing other wireloops of the bulb structure 14.

The collars 64 also include barbs 66, which extend distally from eachcoupler 64. The barbs 66 are sized and arranged such that when the bulb14 is deployed into the LAA 100, such in the manner shown in FIG. 2, thebarbs 66 engage the walls 106 of the LAA, thereby ensuring that the bulb14 maintains its secure position within the LAA space indefinitely oncefully deployed therein.

Though the collars 64 provide the bulb structure 14 with support andstructural stability, it must be noted that the arrangement of wireloops 60 is such that when the bulb 14 is fully deployed within thespace of the LAA 100, the bulb will minimally (if at all) distort,distend or otherwise affect the size or shape of the LAA.

As mentioned above, positioned between cap structure 12 and bulbstructure 14 is a joint assembly 16, such as is shown in FIG. 1-4.Externally, the joint assembly 16 comprises the aforementioned proximalpost 40 to which the wire loops 20 of the cap structure 12 are threadedand engaged; a distal post 44 to which the wires 22 of wire loops 60 ofthe bulb structure 14 are threaded and engaged. An end of each post 40and 44 are held movable adjacent one another within a joint housing 46.Openings 55 of the posts 40 and 44, through which the wires 22 of therespective structures 12 and 14 are engaged are depicted in FIGS. 6-7.

In one embodiment, shown in FIG. 5 the particular arrangement of thepost 40 and 44 ends within the joint housing 46 and the unique structureof the housing 46 provides the device 10 with the a fluid connectionbetween the cap structure 12 and bulb structure 14, allowing the bulbstructure 14 to be rotationally and pivotally articulated relative tothe cap structure 12 to a degree limited only by the interferencepresented by the aforementioned structures themselves, or by thelimitations provided by the joint assembly 16, such as in the mannerdescribed below.

The particular manner in which the cap 12 and bulb 14 are articulablerelative to one another, via the joint assembly 16, is shown in FIGS.6-10. Looking to FIG. 7, the internal configuration of the jointassembly 16 is shown. As can be seen, proximal post 40 includes aproximal neck 41 that terminates at a first or Wdrasler@comcast.netfirstball joint 70 and distal post 44 includes a distal neck 45 thatterminates at a second or second ball joint 74. As shown, the balljoints are not complete “balls” but merely the rounded aspect of thejoint assembly. Their specific shape and dimensions may vary and theparticular manner in which they engage with or extend from theirrespective necks (41/45) may likewise be varied. In some embodiments,the ball joints are ellipsoid or oval in shape. In at least oneembodiment they are substantially spherical in shape above the interfacewith the neck. In at least one embodiment the ball joints have aflattened or “bone shaped” end.

Preferably, a hard metal, such as titanium or other similar materialsuitable for use in medical implantation, is used to construct the partsof the joint assembly 16 including the housing 46, shafts 40 and 44,etc. The first ball joint 70 is contained within a first sleeve 80 ofthe joint housing 46 and the second ball joint 74 is contained within asecond sleeve 84 of the joint housing 46, such that each sleeve 80/84 ofthe housing 46 forms the “socket” for moveably retaining the “ball” ofthe respective ball joint 70/74 in proximal and distal “ball and socket”type connections.

Second sleeve 84 includes a cuff or collar 86 which supports a washer 88and biases the washer 88 between the first sleeve 80 and second sleeve84. Each sleeve has a sleeve opening 90. The sleeve openings 90 iflarger in diameter than the diameter of the proximal neck 41 or distalneck 45 which passes through a respective opening 90, but narrower indiameter than the diameter of the first ball joint 70 or second balljoint 74 thereby retaining the ball joints 70 and 74 within the interior92 of the joint housing 46.

The sleeves 80 and 84 which comprise the joint housing 46 aremechanically secured to one another, or may be chemically or heat weldedor together.

When arranged in the manner shown in FIGS. 6 and 7, the aforementionedcomponents result in a joint assembly 16 wherein two ball joints 70 and74 are able to rotate and pivot independently of each other relative tothe housing 46. The ball joints 70 and 74 are separated by the washer 88so that they do not come in contact with each other and restrict eachother's movement. The washer 150 also prevents the ball joints 70 and 74from moving too far into the center of the sleeves 80 and 84.

The diameter of the openings 90 relative to the diameter of the necks 41and 45 likewise acts as a limit on the degree of motion that the shafts40 and 44 are able to demonstrate relative to the housing 46. This isperhaps best shown in FIGS. 8-9 wherein the extreme limits of thepivotal movement of shafts 40 and 44 are illustrated by the interactionof the opening 90 with the necks 41 and 45. By providing fairly generousopening diameter relative to that of the necks 41 and 45 the shafts 40and 44 may be provided with an extreme amount of motion, therebyallowing the cap 12 and bulb 14 a corresponding amount of articulationrelative to the joint assembly 16 and to one another as illustrated inFIG. 5.

In use, this high degree of articulation allows the device 10 to besuccessfully deployed into left atrial appendages having even the mosttortuous of shapes. For example, in the embodiment shown in FIG. 10, thedevice 10 is deployed within an LAA 100 whose walls 106 define asock-like shape having a substantially angled curve or bend 108. Thebend 108 may define an angle 110 of up to about 70 degrees relative tothe longitudinal axis 112, as defined by the walls 106, which define theinitial LAA opening (ostium 102). Because of the high degree ofarticulation provided by the joint assembly 16, the present device maybe deployed in even the most curvaceous of left atrial appendageswithout undue strain on the surrounding anatomy.

The high degree of flexibility that the joint assembly 16 exhibits,provides the device 10 not only with the ability to be deployed around abend but to deploy around a bend in three dimensions such as in themanner illustrated in FIGS. 11-12. Here the joint assembly 16 is shownrelative to three axes of articulation and rotation 120, 124 and 126.Proximal post 40 extends along the proximal axis of rotation 120; distalpost 44 extend along the distal axis of rotation 124. Each post 40 and44 (by way of the first ball joint 70 and the second ball joint 74 aspreviously discussed) are separately articulable in any directionrelative to the housing axis of rotation 126 which corresponds to andextends along the length of the joint assembly housing 46. By thisassembly and arrangement, each post 40 and 44—and by extension the cap12 and bulb 14 respectively engaged thereto (not shown, see FIG. 10)—maybe positioned and form an angle with the housing 46 that is differentfrom one another and in any direction. In other words: the cap 12 andbulb 14 components may each be positioned in such a manner as to formangles along their respective axis of rotation, in any direction,relative to the housing 46 of the joint assembly 16 of between 0 toapproximately 35 degrees respectively.

A device 10 having such extreme flexibility is not ideal however in allcases. In fact, an unrestricted degree of rotational and pivotalmovement may in some cases make the implantation of the device 10 intoan LAA more difficult. It has been found through laboratoryexperimentation that too much articulation on the bulb side (distal) ofthe joint assembly 16 may in some cases cause complications in properlydelivering the device. Thus, in at least some embodiments, an example ofwhich is shown in FIG. 13-15 potential articulation of the shafts 40 and44 relative to the housing 46 have been limited by modifying thediameter of the opening 90 of sleeve 80 and/or by making the neck 41 ofpost 40 larger relative to the opening 90 of the sleeve 80 so as tolimit the potential motion between the post 40 and housing 46.

If desired, such modification of opening and neck diameters may beprovided instead, or in addition to, that described above to the distalneck 45 and sleeve 84, so as to limit the motion between the housing 46and distal post 44. Any of a variety of relative diameters between thenecks 41 and 45 versus the openings 90 may be provided to the device 10as may be desired.

With the above description, the unique features of the device 10 aremade clear. Some of these features include providing a highly variablearticulable joint assembly that allows for a wide degree of freedom ofmovement between the ostial cap and the bulb structure of the device.This allows the device to be oriented in any manner desired and to beadaptable to any LAA location or configuration. In addition, the bulbstructure is configured such that when fully deployed within the LAA thebulb does not impact the shape of the LAA space.

When delivering the device 10 to the LAA 100 of a patient via catheter200 such as in the manner shown in FIG. 16, the device 10 is folded orcollapsed into a confined state such that the diameter of the device 10is sufficient to allow the device to be loaded into the interior of adelivery catheter 200. The delivery catheter 200 is advanced in to theleft atrium and the delivery tip 202 of the catheter is inserted about10 mm-20 mm past the ostium 102 of the LAA 100. The device 10 is thenadvanced out of the catheter (or a delivery sheath his pulled back fromthe device, etc.) and the bulb structure 14 is advanced into the LAAspace where the distal wire loops 60 self-expand to the deployeddiameter. The deployed diameter being greater than the confineddiameter.

To illustrate the flexibility as well as the physiologic aspect of thebulb structure 14 on the shape of the LAA 100, the device 10 is shown inFIG. 17 such that even when allowed to fully deploy within the confinesof a tortious ostium 102, the bulb structure 14 minimally strains thesurrounding tissue 104.

When properly positioned within the LAA 100, such as in the manner shownin FIG. 17, the bulb structure 14, engages the wall 106 of the LAA 100but does not exert undue pressure or force sufficient to distend theshape of the LAA 100, but rather conforms to the anatomic tortuosityrather than vice versa. Barbs 66 engage the wall to help retain the bulbwithin the LAA 100. Cap structure 30, as previously described, includesseveral features to allow and encourage tissue growth therethrough toensure eventual and compete occlusion of the LAA in the manner desired.

The many features and advantages of the invention are apparent from theabove description. Numerous modifications and variations will readilyoccur to those skilled in the art. Since such modifications arepossible, the invention is not to be limited to the exact constructionand operation illustrated and described. Rather, the present inventionshould be limited only by the following claims.

What is claimed is:
 1. A medical device to treat the LAA, the medicaldevice having a deployed state and a confined state, the medical devicecomprising: a cap, a bulb and a joint assembly therebetween; the caphaving a plurality of layers, a plurality of proximal wire loopsextending from the cap to a proximal post of the joint assembly; thebulb having a plurality of distal wire loops that extend between aterminal post and a distal post of the joint assembly, adjacent distalwire loops being connected one to another by at least one connectioncollar; the joint assembly comprising a first ball joint, a second balljoint and a housing, the proximal post extending proximally from thefirst ball joint, the distal post extending distally from the secondball joint, the housing having a proximal collar and a distal collar,the proximal collar retaining the first ball joint in a first ball andsocket relationship, the distal collar retaining the second ball jointin a second ball and socket relationship; the housing having a housinglongitudinal axis extending therethrough, a proximal longitudinal axisextending through the first ball joint and the proximal post, a distallongitudinal axis extending through the second ball joint and the distalpost, the first ball and socket relationship allowing the proximallongitudinal axis to form an angle of between about 0 to about 35degrees with the housing longitudinal axis in any direction, the secondball and socket relationship allowing the distal longitudinal axis toform an angle of between about 0 to about 35 degrees with the housinglongitudinal axis in any direction.
 2. The medical device of claim 1wherein in the confined state the device is folded into the interior ofa delivery catheter.
 3. The medical device of claim 2 wherein the distalwire loops of the bulb are constructed and arranged to self-expand fromthe confined state to the deployed state within an LAA, the bulb havinga diameter, in the deployed state the diameter of the bulb being greaterthan the diameter in the confined state.
 4. The medical device of claim3, wherein in the deployed state the bulb does not distort the inherentshape of the LAA.
 5. The medical device of claim 3 wherein the distalwire loops are constructed of a plurality of strands of shape memorymaterial.
 6. The medical device of claim 5 wherein the shape memorymaterial is nitinol.
 7. The medical device of claim 3 wherein at leastsome of the distal wire loops include barbs, the barbs constructed andarranged to engage tissue of the LAA when the bulb is in the deployedstate.
 8. The medical device of claim 1 wherein the LAA defines anostium, in the deployed state the cap extending across and completelycovering the ostium.
 9. The medical device of claim 1 wherein theplurality of layers comprise a base layer, a petal layer and asecurement layer, the securement layer being immediately adjacent to anengagement hub, a portion of the engagement hub extending through anopening defined by each of the layers to secure each of the layers toone another to form the cap.
 10. The medical device of claim 9 whereinthe base layer is constructed of a mesh material, the base layercomprising at least two sections of mesh material immediately adjacentto one another.
 11. The medical device of claim 10 wherein the petallayer is comprised of a plurality of continuous and overlapping petalsof a mesh material, the mesh material of the petal layer being the sameor different than the mesh material of the base layer.